How do I sync the animation of objects instantiated at different times?

I'm making a tile-based game like pokemon and I've coded it so that tiles are only instantiated in an area around the player as the overworld is so huge if I loaded it all at once there would be a lot of lag. Everything works great except that because the tiles are now instantiated at different times they start at different places in their animations. For areas like oceans where there are lots of water tiles next to eachother it looks wrong to have their animations not playing at the same time. I want them to always stay synced, but I can't think of an easy way to do it. Is there a good way to do this before I go spend a ridiculous amount of time coding some overhead system to keep track of it?